Felt lining



7 Sept. i942.

mvmon FRANK M. ALLEN ATTORNEY F. M. ALLEN I 2,295,070 1 FELT LININGFiled April 17, 1939 leaving an uneven base for the Patented Sept. 8,1942 v UNITED STATES PATENT OFFICE I FELT LINING Frank M. Allen, Summit,N. J.. assign: to

Inc., a corporation of New Congolcum-Nairn York Application April 17,1939, Serial No. 268,250 3 Claims. (Cl. 117-140) This invention relatesto felt lining sheets and I lates especially to felt lining sheetssuitable, for example, forinterposition between a covering material suchas linoleum and a support such as a floor, wall, article of furniture orthe like.

Heretofore felt lining sheets have been provided between coveringmaterials such as linoleum and a support such as a floor. The'felt bondthe lining sheet to the support using a hand 'spread adhesive, andthereafter to bond the linoleum to the upper side of the lining sheetusing an additional quantity of adhesive. This adhesive is usually ofwater soluble character. Where the lining is of dry or unimpregnatedfelt it constitutes a' relatively weak membrane susceptible ofde-lamination under varying service conditions and is particularlysubject to damage during the period immediately following installationand before the adhesive dries out and hardens. When such dry felt isused the adhesive sets fairly rapidly due to the fact that the felt isreadily wetted by the solvent (usually water) of the adhesive and suchsolvent is quickly dispersed through the dry felt. The fact that themanufacture and installation thereof. it re- I results in the i phalticbinder than is present.in the saturated thefad'hesive sets rapidly isdisadvantageous,

however, when portions of the covering material such as linoleum are tobe cut out and replaced by special insets. In such cases the adhesiverapidly becomes bonded to the dry felt to such an extent that some ofthe dry felt pulls away from the body of the felt lining when thedesired portion of the covering material is removed, thus insets. (whenfelt highly impregnated with a bituminous saturant as, for example, afelt of rag and paper fibre impregnated to the extent of about the feltat and adjacent one side of the sheet 50% (one part saturant to one partfibre) with a bituminous material having a softenin Point (determined bythe known ball and ring method) of about 115 F. to 200 F., is used as aninterliner in the manner mentioned above, the felt sheet does notlaminate'under service conditions and is water and moisture-resistant.Moreover,

. due to the greater imperviousness of the saturated felt, the water inthe adhesive evaporates slowly causing veryslow setting of the adhesive.This slow setting of the adhesive facilitates cuttions of the bindermaterial inthe different parts dent to lining sheets heretofore used.

ting out desired portions of the covering mate rial after theinstallation thereof and the re placing of such cut-ont portions withinsets I Such highly impregnatedfelt has serious ,disadvantageahowever,inasmuch as the tendency' pf the saturated felt to excessively retard'setting*ufj-* the adhesive layersibothaboveand-below thefeltffinishedinsltallation being subject to'denting even under light loadsfor several days". 7 until the adhesive has hardenedanfeven more seriousdiillculty incident to the useof such high 1y impregnated felt is thatsuch 'felt'is extremev ly dimcult to remove from a support after it has7 become bonded thereto. Dry felt can bequit'e readily removedespecially when a water dis: sociable adhesive has been'used tobondittea" a support, inasmuch as the felt is readily permeable to waterandpermits the water'to pass through the felt and dissociate the adhesiveso that the felt and adhesive can be readily removed. When a saturatedfelt has. been used. its lack of per meability makes it extremelydiflicultjandjcostly I to remove after it has once bonded to asupport;Felt linings impregnatediuniformly through-' out but containing alesser-percentage-of as felt above described have also been used aslining sheets but such felts are an unsatisfact r compromise between dryfelt on "the one hand and highly impregnated felt on the other hand.When the degree of impregnation is 'low it re-. sults in too rapidsetting of the adhesive for inset work and in too slow setting of theadhesive layer that bonds the felt lining to the support.-

It is apurpose of this invention to afford a felt lining sheet thatovercomes difflculties such as those hereinabove referred "to which areinci- It is a feature of lining felt embodying this invention that whileit contains bituminous material (or equivalent waterproofing bindermaterial) throughout, the bituminous material is non-uniformlydistributed in the sheet so that contains substantially more of. thebituminous material than the felt at and adjacent the other side of thesheet. It is a further feature of this invention that a lining felt ofthe character referred to is installed'with the side comprising thelesser amount of bituminous material adjacent the support and with theside comprising the greater amount of bituminous material adjacent theoverlying cover i!rig material. Further features of this invention elateto the proporadvantages thereof, it will be described in con nectionwith certain specific examples of the practice thereof.

A lining sheet which I have found to be very satisfactory forpositioning between a support such as a floor and an overlying coveringmaterial such as linoleum consists of a felt sheet of rag and paperfibres comprising a body portion that contains about 5% to about 30% ofa bituminous binder. The percentages just mentioned and mentionedelsewhere in the specification and in the claims represent thepercentage by weight of the defined constituent in-relation to the totalweight of the impregnated sheet or sheet zone in question. Preferablythe amount of bituminous bind.- er in the body portion of the sheet iswithin the range of about 5% to about 20% and in usual practice is aboutto about The body portion of the sheet, aside from the bituminousbinder, consists essentially of fibrous material, although the felt maycontain a minor proportion of filler material. One side of such feltsheet is impregnated with a bituminous binder so that a portion or zoneof the felt at and adjacent one side of the sheet contains more than ofhituminous material and preferably contains about to about of bituminousmaterial. It is to be noted that the lining felt contains bituminousbinder throughout but this binder is so apportioned that the liningsheet is divided into two dissimilar layers or zones, one layer or zoneat and adjacent one side of the sheet containing a greater proportion ofbituminous material than the layer or zone at and adjacent the otherside of the lining sheet. Usually it is desirable that the difference inthe proportion of binder between the two layers or zones be greater thanabout 10%, preferred results being obtained when the difference inbinder is about 20% to about 50%. For the body portion or layer of thesheet containingthe lesser proportion of bituminous binder a bituminousbinder having a softening point of about 160 F. to about 170 F. ispreferably used, although the softening point of this biterials having asoftening point of about F.

to about 130 F. being advantageous.

One typical satisfactory product which I have produced comprises a bodyportion or zone at and adjacent one side of the sheet containing about t12% of bituminous binder, about 80% of fibre (e. g., mixed rag, wood andpaper fibres) and the balance mineral filler material. Such a sheet isapproximately .050 inch to .055 inch in thickness and weighs about onepound perwsquare yard. The asphaltic binder has a softening pointofabout 160 F. One side of thissheet is impregnated with a bituminousmaterial having a softening point'of-about F. The amount of impregnatingmaterial applied approximates 0.2 pound per square yard and itpenetratesabout one-fourth the thickness of the sheet; thus producing a zone at oradjacent one side of the sheet which as a whole contains about 50% ofbituminous material. The bituminous inaterial in the body portion of thefelt sheet is distributed as much as possible in the form of particlesbinding the fibres together but leaving as large a propor-'- tion aspossible of the surface of the fibres in an uncoated condition, therebypromoting the absorptiveness and permeability of the body portion of thefelt. While the felt sheet'has a layer at and adjacent one side thereofwhich contains considerably more bituminous material than the bodyportion of the sheet, the portion of the sheet tuminous binder issubject to wide variation and bituminous binders having a softeningpoint between the range of F. and 200 F. may be advantageously employedaccording to this. invention; I

The felt lining sheet may be produced by first preparing a sheet of ragand paper fibres comprising asphaltic material of the character and inthe limited amount required for the body portion thereof. Thereafter,the sheet of felt is impregnated from one side only with a bituminousmaterial which only penetrates about one-eighth to one-third of thethickness of the sheet. The bituminous material thus subsequentlyapplied to one side only of the sheet preferably has a softo one side ofthe sheet has a softening point of cent the floor is such that the waterof the linolecontaining the greater amount of bituminous material ispreferably also somewhat permeable, although the body portion of thesheet is consid erably more permeable. When a lining sheet of thecharacter above described is installed, this is preferably donebybonding the lining sheet to thesurface of a support such as a floor byordinary linoleum cement in a water-activated condition. The side of thelining felt containing the lesser proportion of bituminous material isbonded to the support. A covering material such as sheet linoleum isthen bonded to the upper side of the lining felt by ordinary linoleumcement.

When a felt lining sheet is made and installed as above described, Ihave found that the defects incident to the employment -of the feltlining sheets heretofore used are overcome and that the new structure isvery advantageous. In the first,

place, no part or layer of the lining sheet is sufficiently weak to delaminate under service conditions. During the installation the porosityand permeability of the layer of the lining felt adjaum cement israpidly absorbedby the felt, thus permitting a rapid setting of thecement used for bonding the lining to the floor. On the other hand, thecement which is used for bonding the linoleum to the upper side of thelining sheet does not set as rapidly as the cement used for bonding thelining sheet to a floor due to the fact that the upper portion or layerof the lining sheet is much less permeable than the lower portion to thewater used in the adhesive and therefore the dissipation of the waterfrom the adhesive is retarded, thus retarding the setting of theadhesive. The delayed setting of the adhesive which bonds the linoleumto the lining sheet permits the lifting out of desired portions from thebody of the linoleum from periods up to 1 /2 to 2 hours after thelinoleum has been initially about 20 to 25 rial which is desired like,and together wi h any one side of. f ditions the bituminousmaterialpenetrates bonded to the lining sheet without damaging the felt of thelining sheet in any way. This facilitates the positioning of borderstrips and other insets in the linoleum after the linoleum has beenbonded to the lining sheet.

It is a further advantage of my improved iining sheet that while thelining sheet will not delaminate under service conditions, the removalof the overlying linoleum is facilitated, inasmuch as the body portionor layer of the lining'sheet containing the lesser proportion ofbituminous binder can be laminated or split by pulling the linoleum fromthe fioor.

ing sheet or zone having the lower binder content affords a cleavagelayer which permits the sheet linoleum to be readily stripped from thefloor. Preferably the lamination strength or resistance to splitting ofsuch body portion or zone of. the lining sheet should be slightly lessthan the strength of the backing fabric or other foundation sheet of thelinoleum which is normally pounds per foot of width of the goods. Afterthe sheet linoleum has been stripped from cleavage in the body portionor zone of lower binder content it is a relatively simple matter toremove the portion of the felt of the lining sheet which remainsadherent to the floor, inasmuch as this portion is readily permeable towater so that the water can strike through it and soften or dissociatethe adhesive used for bonding the lining sheet to the floor. As has beenmentioned above, 'it is a very diificult procedure to attempt to removea highly impregnated lining felt from the floor because of itsimperviousness to water.

A lining sheet, according to this invention, can be produced in severalways. Preferably the lining sheet is produced by first preparing afurnish suitable for a paper-making operation, which furnish includes anamount of bituminous matein the body portion or layer of the liningsheet. In an application of William Y. Irwin, Jr., executed on even dateherewith (Serial No. 268.345, filed April 17, 1939); is described onesuitable method of preparing and felting such a furnish. As described inthis application a paper-making furnish is prepared containingbituminous material recovered from scrap bituminized fibrous material,together with fibres derived from wood, rags, newsprint or the fillermaterial such as mineral filler, pigments, particles of hardenedoxidized oil or the like that may be present in the scrap. The furnishcontains uncoated fibres and the bituminous material is distributedthrough the furnish in the form of particles so that when a sheetfurnish by a paper-making operation a major proportion of the surface ofthe fibres in the sheet is'substantially uncoated although theparticlesof bituminous material distributed throughout the sheet serveto bond the fibres of the sheet together. After the sheet of felt thusproduced has been dried, the felt, according to the present invention,is impregnated on one side with a bituminous material in a heatliquefied condition. This can be done, for, example, when the sheetcomes from the drying unit of the paper machine. In making a liningsheet, according to the example above given, bituminous material havinga softening point or about 115 .FZ is heated to a temperature of about300 FI-ancl -is applied to the sheeted felt. Under such con- 1 aboutone-eighth. to one-third through The body portion of the linsheetusually penetrates sheet. The use of bituminous material having arelatively low softening point is desirable, inasmuch as such bituminousmaterial more rapidly. penetrates substantially into the body of thefelt and gives greater flexibility to the product than is obtained withbituminous material of higher softening point. The bitumen the sheet soas to produce a zone in which the proportion of bitumen graduallydiminishes toward the inner side thereof.

especially desirable, inasmuch as the body portion of the feltcontaining the. lesser proportion of bituminous binder is left in acondition which readily permits the absorption and permeation of wateror other liquid. This is due to the fact that a large proportion offibres is not coated with the bituminous binder, the fibres being bondbythe distributed bitumen particles. body portion is thus left so as topermit the ready ation by water or other solvent, 9. water activatedadhesive used to bond the lining sheet to a sub-surface sets morequickly, inasmuch as the water can disperse very readily into the bodyportion of the lining. Moreover, when the lining sheet is stripped fromthe floor with cleavage in the body portion or zone of lower bindercontent the felt remaining on the floor can be more eadily removed,inasmuch as water can very readily penetrate through the felt and.dissociate the adhesive that bonds it to the floor.

A lining sheet having a body portion which has a high degree ofpermeability and absorptiveness for water or other solvent can beproduced by other methods. In general such a felt can be produced bydistributing bituminous material in the form of finely divided throughuncoated fibres in a paper-making furnish and then producing a felt fromthe furnish by a paper-making operation as by the use of a paper-makingcylinder or a Fourdrinier machine.

of felt is' formed from the the body of the inabove referred .nousmaterial. be produced nous material (e. g., and binder) than And afterthe felt sheet has been produced containing the bituminous material inthe form of discrete particles uniformly distributed through theuncoated fibres of the felt, the felt can then be treated so as toimpregnate the adjacent one side of the sheet with additional bituminousmaterial. This is preferably done by applying the bituminous material ina. heat liquefied condition.

Another method of producing a lining sheet having a partiallyimpregnated body portion or layer is to distribute bituminous materialin an emulsified condition together with fibres in a furnish. When thisis done" the on the fibres ing product having the appearanceof beingindividually coated with a thin coating of the bitumi- For example, afelt sheet can first from a taining emulsified bituminous binder so asto produce a sheet containing approximately 15% of bituminous material.After this sheet has been dried it can be treated on-one side thereof sothat a layer of felt at and adjacent one side of the sheet will containsubstantially more bitumiabout equal parts of flbre the felt at andadjacent the other side of the sheet. A lining character is, however,regarded as somewhat less desirable formost purposes than the typehereto wherein the fibres in the body applied to the A lining feltproduced as above described is 7 absorption and permediscrete particlespaper-making furnish'con- I sheet of this portion of the sheet are forcoated with the bituminous material. When the fibres are coated withbituminous material in the body portion of the sheet such body portionof.

the sheet is less absorptive-and less permeable to water. This lack ofwettability, permeability and absorptiveness of thebody portion of thesheet interfereswith the rapid absorption of the water used in thecement for bonding the lining sheet to a sub-surface. Moreover, the lackof wettability and permeability of the body portion of the sheetinterferes with the removal of any felt which remains on the sub-surfaceafter the lining sheet has been stripped from the sub-surface withcleavage at the body portion or layer of the lining sheet.

A lining sheet embodying this invention and installations using suchlining sheet are shown for purposes of exem'plification in theaccompanying drawing wherein Figure 1 is a sectional elevation of aportion of ordinary sheet linoleum secured to a support using a liningsheet according to this invention, a portion of the linoleum sheet beingstripped from the support;

Figure 2 is a sectional elevation of a portion of the lining sheet perse; and v Figure 3 is a sectional elevation of the lining sheet incombination with another covering material and a suppo Referring toFigures 1 and 2, sheet linoleum is indicated generally by the referencecharacter It. The sheet linoleum includes a layer ll of linoleumcomposition which presents an ornamental and wear-resisting surface andwhich is integral with a strain-resisting backing fabric 12 which may,as shown, be in the form of a suitable heavy fabric such as burlap.Interposed between the sheet linoleum and the support is is a liningsheet which is indicated generally by the reference character I l. .Thelining sheet consists of a body portion or layer l 5 which comprises alimited amount of uniformly distributed bituminous binder. On the sideof the sheet adjacent the sheet linoleum is a layer It which contains agreater amount of bituminous material than the body portion 15. The bodyportion or layer I5 is bonded to the support l3 by a layer of adhesivel1 and the layer i6 is bonded to the lower side of the sheet linoleum bya layer of adhesive i8.

In Figure 1 a portion of the linoleum is shown as pulled away from thesupport it in order to indicate what happens when the linoleum is thusstripped from the support. The weakest bond between linoleum and thesupport is at the body portion or zone iii of the lining sheet. Asindicated in the drawing, cleavage occurs in this zone leavingtheadhesive layer l1 and a part of the felt of layer ll bonded to thefloor. After the linoleum has been thus removed, a solvent, e. g..water, adapted to dissociate the adhesive of adhsive layer I! can beapplied to the felt which remains bonded to the floor and since the feltis very permeable to the solvent, it is possible to quickly and easilyremove the felt and adhesive from the surface of the support.

' In Figure 1 this invention has been indicated in connection withconventional sheet linoleum. It is apparent, of course, that lining feltembodying this invention may be used in connection with other kinds ofcovering materials. For example, it is apparent that this invention canbe used in connection with sheet linoleum having an impregnated feltbacking fabric instead of a woven the most part undepth within nousbinder.

the lining sheet can shown as bondedto the upper side of the liningsheet containing the greater proportion of bituminous binder by adhesivel8 and the lower side of the lining sheet is bonded to the support It byadhesive I1.

In using a lining sheet according to this invention the lining sheet isnormally first bonded to the floor and thereafter the covering materialis bonded to the upper side of the lining sheet.

However, it is not beyond thescope of this lnvenof a preformed coveringstructure, and then bond the lower surface of the lining the lesseramount of bituminous binder to a support by means of a suitable cementor adhesive.

In using the lining sheet any ordinary linoleum adhesive may be used. Asuitable linoleum adhesive which is extensively used at the present timeconsists of a mixture of lignin and clay in the proportion of one partof lignin to about one part of clay together with suflicient water torender it spreadable. Such an adhesive drying out of the water. Thistype of adhesive isi dissociable by water after it has hardened so thatthe adhesive can be readily removed from a support to which it has beenapplied upon application of water thereto.

It has been mentioned that it is preferred to make a felt lining sheetembodying this invention by first'making a felt containing bituminousmaterial uniformly distributed therethrough by a paper-making operationand thereafter; applying bituminous material in a heat liquefiedcondition to one side only of the felt sheet thus produced. It isapparent, however, that a felt lining sheet embodying this invention canbe made in other ways. For example, a preformed felt can be partiallyimpregnated with bituminous material as by impregnating the felt inbituminous material thinned with a suitable solvent, removing thesolvent, and thereafter additional bituminous mate rial can be appliedto one side only of the felt. This method is not preferred, however,inasmuch as the portion of the felt containing the lesser amount ofbituminous binder is less absorbent and permeable to water than when thefelt is made so as to contain substantially uncoated fibres bondedtogether with particles of a bitumi- Moreover, instead of applying thebituminous material to one side only of the felt sheet ina heatliquefied condition, the bituminous material can be applied when thinnedby a solvent or when in the formof anemulsion, provided the bituminousmaterial as applied is concentrated at one. side only of the liningsheet. The bitumen should penetrate to a substantial the felt ratherthan being in the form of a superficial coating, inasmuch as when thebituminous material penetrates into the felt some porosity of the sideor layer of the felt sheet comprising the greater amount of bituminousmaterial can be retained. It is desirable to have the lining sheetpermeable to water throughout the thickness thereof, although, asexplained hereinabove, the lining s t should be substansheet containinghardens by the .ially less permeable at the side of the sheet com-Jrising the greater proportion of bituminous iinder than in the bodyportion or layer of the sheet containing a lesser proportion of thebinder. in order that the zone of the'lining sheet con- ;aining thegreater amount of binder retain at least some permeability it is usuallydesirable that the proportion of binder in this zone taken as a whole benot in excess of about 60%, although if substantially completeimpermeability is desired an even greater quantity of bitumen can beused in this zone.. Any suitable bituminous binder material may be usedsuch as asphalts, pitches, etc.

Reference has been made hereinabove to the use of bituminous material asa waterproofing binder material for thefelt lining sheet. This has beendone because bituminous materials are regarded as superior to otherbinder and waterproofing materials for the'purposes of this invention.However, it is notg entirely without the scope of some aspects of myinvention, broadly considered, to utilize other waterproofing bindermaterials. For example, a felt can initially be partially impregnatedsubstantially uniformly throughout with a bituminous binder as describedhereinabove and thereafter one side of the felt can be treated with awaterproofing binder material such as wax, drying oils, etc. so as todecrease the permeability of the lining felt on one 3 side only thereof.Moreover, in,the body portion or layer of the lining sheetotherwaterproofing binder materials may be used such as rosin, paraflinwax, etc.

Although this invention has been described in connection with certainspecific embodiments thereof, it is to be understood that this has beendone merely for purposesof illustration and that the scope of thisinvention is to begovemed by the language of the following claims.

I claim:

1. As an article of manufacture, a flexible felt lining sheet the fibersof which constitute a resilient mass substantially as formed by afelting operation, said felt lining sheet containing bituminous materialthroughout the-thickness thereof and comprising a first zone at andadjacent one side thereof that contains about 5% to about 30% ofbituminous material and a zone at and adjacent the other side of saidsheet that contains over about. 30% of bituminous material and thatcontains at'least about 20% more of bituminous material than said firstzone, said lining sheet being at least somewhat permeable to moisturethroughout the thickness thereof, the fibers of said second zone beingfree of a substantial 55 amount of surface uncoated by bituminousmaterial, and said first zone containing fibers substan- 5 absorptive ofmoisture than said second zone.

2. As a lining sheet, a flexible sheet of fibrous felt containingbituminous material throughout the thickness thereof and permeable tomoisture throughout the thickness thereof, there being a first zone atand adjacerit one side of the felt andconstituting the major part of thethickness of the'felt containing about to about 20% of bituminousmaterial in the'form of discrete particles interspersed among andbonding the fibers in said zone together leaving the major portion ofthe surface of the fibers in said zone uncoated with bituminous materialand leaving said zone in a water-absorptive and readilypermeablecondition, and there being a second zone at and adjacent theother sideof said felt and constituting at least about one-eighth the thickness of.said felt containing about 40% to about 60% of bituminous materialwhich occurs r as a coating for substantially all of the surface of theindividual fibers in said second zone and "bonds the fibers in said zonetogether, but which does not coat the surface of the-felt sheet as awhole and leaves said second zone permeable to moisture so as to permitgradual dissipation of o moisture therethrough, said second zone beingsubstantially less water-absorptive and less permeable to moisture thansaid first zone.

3. As a lining sheet, a flexible sheet of fibrous felt containingbituminous'material throughout the thickness thereof and permeable tomoisture throughout the thickness thereof, there being a first zone ofsubstantial depth at and adjacent one side of said felt sheet containingabout 5% to about 30% of bituminous material which bonds 40 the fibersin said zone together, but which leaves said zone readily permeable tomoisture, and. 'there being a second zone of substantial depthat andadjacent the other-side of said felt sheet containing more than about30% ofbituminous material which occurs as a coating for substantiallyall of the-surface of the fibers in said second zone and bonds thefibers in said zone together, but which does not coat the surface ofsaid felt sheet as a whole and leaves said second zone P rmeable tomoisture so as to permit gradual dissipation .of moisture therethrough,the proportion of bituminous material in said first zone being at leastabout 10% less than the proportion of bituminous material in said secondzone, and said first zone being substantially more permeable to moisturethan said second zone.

FRANKM.ALT.|EN.

